Obesity has become a major health problem in the United States and worldwide. In the United States alone, it has been estimated that obesity accounts for more health care expenditures than any other health condition, including smoking. Obesity has been linked to high blood pressure which leads to hypertension, high levels of blood glucose associated with diabetes, high concentrations of blood cholesterol and triglycerides which are associated with cardiovascular disease, certain types of cancer, increased stress on weight-bearing joints which can lead to arthritis, depression, sleep apnea and gall bladder disease. Many solutions to achieve weight loss for the treatment of obesity have been proposed. They can be summarized and placed into four different categories. Physical exercise, dietary restrictions, pharmaceuticals and surgery.
An substantial increase in physical exercise has long been recognized as a method of preventing weight gain. Vigorous exercise is normally recommended since this results in a substantial increase in the energy expended by a person. Whenever there is more energy expended than taken in through the consumption of food, weight loss occurs. This solution has been proposed by physicians and those persons in the health care area for many years. When exercise is performed on a regular basis an additional benefit is realized. This regular exercise increases the body's rate of metabolism. An increase in the rate of metabolism will result in more energy being expended even when a person is resting. This is still the preferred solution today. However, many individuals do not have the time or stamina to do these vigorous exercises on a routine basis. In addition, the morbidly obese individuals risk further damage to their health, for example by heart attacks, from such exercise.
Another solution involves dietary restrictions. This involves eating the “right” kinds of foods, for example those which have a low fat and sugar content. There are many food available today which are considered to be “diet” versions of popular foods. The most popular of these is diet soda in which a chemical, such as Saccharin, is substituted for the sugar. The chemical does not have any calories therefore the person drinking the soda will not consume any calories. Also the amount of food consumed should be limited. A healthy body will give an indication that the person has consumed enough food and is “full”. If this signal is ignored, the individual tends to expand the stomach, Ghrelin will be secreted by the stomach as a result of it being distended. Ghrelin in turn stimulates the secretion of Agoti-related protein (Agrp) and Neuropeptide Y (Npy) within the hypothalamus thereby stimulate food intake. The size of food portions in the marketplace, including restaurants, has progressively increased which has resulted in the consumer ignoring the “full” indicator and eating all the food that has been purchased.
Another solution involves the use of pharmaceuticals such as stimulative or appetite suppressive drugs. While this may be a satisfactory solution for many, the use of pharmaceuticals in the treatment of obesity is not without drawbacks. For example, individuals using such drugs are at risk of becoming addicted or ill-affected by the side effects of the drugs. Further, these drugs oftentimes become less effective over time due to the development of drug tolerances by the body.
Surgical solutions to the obesity problem have also been proposed. These involve reducing the volume of the gastric cavity by creating a small pouch gastric bypass, such as a Laparoscopic gastric bypass and a Roux-en-Y gastric bypass. Another method of reducing the volume of the gastric cavity involves surgically placing a balloon or inflatable bladder adjacent to or into the stomach and inflating the balloon. This enables the person to feel “full” after consuming a relatively small portion of food. A number of gastric balloon systems have been proposed. In one type of system the balloon is inserted into the stomach and inflated to a specific volume. The volume of the balloon remains constant over the time period that the balloon is employed to cause a weight loss. A drawback to this has been observed. In many cases the stomach expands to accommodate the balloon and recovers a portion or all of its former capacity for food intake, thereby defeating the purpose of the balloon and reducing the effectiveness of the treatment.
Another type of gastric balloon system permits the volume of the gastric balloon to be varied. The purpose of changing the volume of the balloon is to provide periods of feelings of relief and well-being to the patient. One system, disclosed in U.S. Pat. No. 4,133,315 to Berman, utilizes a filling/release tube coupled to the balloon and which in one embodiment extends surgically through the stomach wall and through the wall of the abdomen. Fluid can be pressurized into the balloon through the tube to cause the balloon to expand, or it can be released/evacuated from the tube to permit the balloon to collapse, thereby varying the volume of the balloon.